Sen. Barack Obama has gained ground on Sen. Hillary Clinton among likely Democratic voters in Tuesday's primary, but a Quinnipiac University poll out today shows Clinton still leads Obama 48 to 43 percent.

While Clinton's support has remained stable in the final weeks of the primary, the poll clearly shows Obama picked up support to narrow the gap. Clinton led Obama 49 to 32 percent in a poll two weeks ago.

"Obama has put together a coalition of blacks and independents to dramatically narrow the gap in just the last few days in New Jersey," said Clay Richards, assistant director of the Quinnipiac University Polling Institute. "But the big question remains: Will there be enough of these new, young, first time voters showing up to pull a surprise on Super Tuesday?"

On the Republican side, the withdrawal last week of former New York mayor Rudy Giuliani has left Arizona Sen. John McCain the clear favorite. McCain leads former Massachusetts Gov. Mitt Romney 52 to 30 percent among likely Republican voters, according to the poll. Former Arkansas Gov. Mike Huckabee and Texas Congressman Ron Paul get 6 percent each, the poll showed.

"With Giuliani out of the race, New Jersey Republicans have flocked to McCain," Richards said.

McCain and Obama have scheduled rallies in New Jersey today, while Clinton and Romney are sending surrogates.

Among Democratic voters, the poll shows 78 percent of those supporting Clinton and 78 percent of those supporting Obama say they are not likely to change their minds.

That loyalty suggests the outcome of the election will depend on who casts ballots, and because of her organizational support, that would seem to favor Clinton.

"Three things will decide this race, turnout, turnout and turnout," Richards said. "New Jersey Democratic party organizations are famous for getting out their vote in primary elections. When added to Clinton's strength among women, this could bring home the victory."